ci: remove VCPKG_ROOT env to suppress mismatch warning

Signed-off-by: Vincent Jardin <vjardin@free.fr>

Author: vjardin

.github/workflows/ci.yml

@@ -163,8 +163,6 @@ jobs:
   build-windows:
     name: Build Windows
     runs-on: windows-latest
-    env:
-      VCPKG_ROOT: C:\vcpkg
     steps:
       - uses: actions/checkout@v4